Microfluidic device with various surface properties fabricated in multilayer body by plasma etching

Abstract

The technology is based on the plasma etching of organic polymer sheets partially protected by a metallic mask. The originality of the process is to pattern the surface properties by the same physical means as the one used for the three dimensional fabrication and simultaneously to this fabrication. Surface properties mean, but are not limited to hydrophobicity hydrophilicity, conductivity, reflectability, rugosity and more precisely the chemical and/or physical state of the surface. It is also possible to generate the desired fonctionalities, for instance carboxylic acid, ester, ether, amid or imide, during the etching process. The patterning of the different properties may be achieved by two different techniques that may be used separately or simultaneously.

1 . A microfluidic device comprising: 
 a multilayer body comprising at least one first polymer layer, said at least one first polymer layer comprising at least one micro-structure for performing analysis using electrochemical fluid properties, said micro-structure having a hydrophobic surface portion and a hydrophilic surface portion.    
   
   
       2 . A microfluidic device according to  claim 1 , wherein said multilayer body further comprises at least one protective layer, said hydrophilic surface portion is formed in said first polymer layer and said hydrophobic surface portion is formed in said at least one protective layer.  
   
   
       3 . A microfluidic device according to  claim 1 , wherein said hydrophobic surface portion is a metal.  
   
   
       4 . A microfluidic device according to  claim 3 , wherein said metal serves as an electrode.  
   
   
       5 . A microfluidic device according to  claim 4 , wherein said electrode is provided with electrically conductive leads for connection to a source of electrical power.  
   
   
       6 . A microfluidic device according to  claim 1 , characterized in that said micro-structure is formed with a thickness corresponding to the entire thickness of said first polymer layer.  
   
   
       7 . A microfluidic device according to  claim 1 , wherein said micro-structure comprises at least one of a micro-channel, an opening, a reservoir, a fluid reservoir and a well.  
   
   
       8 . A microfluidic device according to  claim 1 , wherein said multilayer body further comprises at least one supplementary layer covering said micro-structure to seal said at least one micro-structure with at least one access hole connected to said micro-structure.  
   
   
       9 . A microfluidic device according to  claim 1 , wherein said multilayer body further comprises at least one supplementary layer, said supplementary layer comprising at least one micro-structure.  
   
   
       10 . A microfluidic device according to  claim 1 , wherein said multilayer body further comprises a second polymer layer having surface properties different from the surface properties of said first polymer layer.  
   
   
       11 . A microfluidic device according to  claim 10 , wherein said second polymer layer is adjacent to said at least one first polymer layer, and said at least one micro-structure is formed between said first and second polymer layers, one of said hydrophilic surface portion and said hydrophobic surface portion of said micro-structure is in a first surface section of said first polymer layer and the other is in a second surface section in said second polymer layer.  
   
   
       12 . A microfluidic device according to  claim 10 , wherein said first polymer layer is an electrically insulating foil and said second polymer layer is a lamination, said microfluidic device is further comprised of a micro-structure arranged between said insulating foil and said lamination.  
   
   
       13 . A microfluidic device according to  claim 1 , wherein the multilayer body includes a network of interconnected and/or interconnectable hollow and/or solid micro-structures of partially different physical or chemical surface properties.  
   
   
       14 . A microfluidic device according to  claim 1 , wherein the surface properties of at least one layer of said multilayer body is further modified by at least one physical or chemical treatment.  
   
   
       15 . A microfluidic device according to  claim 14 , wherein said at least one physical or chemical treatment is a deposition of a metal or a polymerization reaction.  
   
   
       16 . A microfluidic device according to  claim 1 , wherein the microfluidic device is at least partially provided with an electrical structure which is formed in a manner that a fluid is displaceable by an electric field generated by said electrical structure.  
   
   
       17 . A microfluidic device according to  claim 16 , wherein said electrical structure is provided in a manner that charged particles selected from a group consisting of ions, DNA, molecules, cells or viruses are displaced in an electric field generated by said electrical structure.  
   
   
       18 . A microfluidic device according to  claim 1 , characterized in that surface sections of said micro-structure have different conductivities, reflectabilities, rugosities, sieving rates, different corrugations, and/or different physisorption and/or different chemisorption rates of a particular material.  
   
   
       19 . A microfluidic device according to  claim 1 , wherein said multilayer body further comprises at least one compound immobilized on at least one surface portion of said micro-structure.  
   
   
       20 . A microfluidic device according to  claim 19 , wherein said compound is immobilized on said surface portion by physisorption, chemisorption, covalent binding or ionic binding.  
   
   
       21 . A microfluidic device according to  claim 20 , wherein said compound is an affinity agent selected from the group consisting of an antigen, an antibody, an enzyme, a peptide, and DNA.  
   
   
       22 . A microfluidic device according to  claim 1 , further comprising a coupler coupling the microfluidic device to an analytical system.  
   
   
       23 . A microfluidic device according to  claim 22 , wherein said analytical system is selected from the group consisting of a liquid chromatograph, a capillary electrophoresis apparatus, an isoelectric focusing system, a size discrimination device and a mass spectrometer.  
   
   
       24 . A microfluidic device according to  claim 1 , wherein at least one portion of the microfluidic device has the shape of a tip.  
   
   
       25 . A microfluidic device according to  claim 24 , wherein the tip is selected from the group consisting of an electrospray, a nanospray tip, a sensor tip or a fluid dispenser tip.  
   
   
       26 . A microfluidic device according to  claim 1 , wherein at least one portion of said micro-structure is able to accommodate a medium.  
   
   
       27 . A microfluidic device according to  claim 1 , wherein at least one portion of said micro-structure is filled with a medium.  
   
   
       28 . A microfluidic device according to  claim 27 , wherein said medium is selected from the group consisting of a fluid, a solid or a gel.  
   
   
       29 . A microfluidic device according to claims  27 , wherein said medium contains charged particles.  
   
   
       30 . A microfluidic device according to  claim 29 , wherein said charged particles are selected from the group consisting of ions, molecules, peptides, DNA, antigens, antibodies, enzymes, cells and viruses.  
   
   
       31 . A microfluidic device according to  claim 26 , wherein said medium comprises beads.  
   
   
       32 . A microfluidic device according to  claim 1 , wherein the analysis is at least one of a chemical assay and a biological assay.  
   
   
       33 . A microfluidic device according to  claim 32 , wherein said at least one of the chemical assay and the biological assay is selected from the group consisting of an immunological assay, an enzymatic assay, a DNA assay, a peptide assay and a cellular assay.  
   
   
       34 . A microfluidic device according to  claim 1 , wherein said analysis includes one of a chemical synthesis reaction and a biological synthesis reaction.  
   
   
       35 . A microfluidic device according to  claim 1 , wherein said analysis includes a performance of a separation selected from the group consisting of electrophoresis, chromatography and mass spectrometry.  
   
   
       36 . A microfluidic device, comprising: 
 a multilayer body comprising at least one polymer layer coated with at least one protective layer having a recess, said polymer layer having a micro-structure at said recess, a wall of said micro-structure having a hydrophobic surface portion and a hydrophilic surface portion.    
   
   
       37 . A microfluidic device according to  claim 36 , wherein said hydrophobic surface portion is a metal.  
   
   
       38 . A microfluidic device according to  claim 37 , wherein said metal serves as an electrode.  
   
   
       39 . The microfluidic device according to  claim 36 , wherein said micro-structure comprises at least one of a micro-channel and an opening selected from the group consisting of a reservoir, a fluid reservoir, a reaction chamber, a well, an access hole and a combination thereof.  
   
   
       40 . The microfluidic device according to  claim 39 , wherein the micro-channel is parallel or perpendicular to a surface of said polymer layer.  
   
   
       41 . The microfluidic device according to  claim 36 , wherein said protective layer is made of an electrically conductive material.  
   
   
       42 . The microfluidic device according to  claim 36 , wherein said micro-structure has a thickness corresponding to the entire thickness of said polymer layer.  
   
   
       43 . The microfluidic device according to  claim 36 , wherein said multilayer body further comprises at least one supplementary layer.  
   
   
       44 . The microfluidic device according to  claim 43 , wherein said supplementary layer contains at least one micro-structure.  
   
   
       45 . The microfluidic device according to  claim 43 , wherein said supplementary layer covers said micro-structure to seal the micro-structure with at least one access hole connected to said micro-structure.  
   
   
       46 . The microfluidic device according to  claim 36 , wherein said micro-structure has at least one dimension in the range of about 0.1 to about 1,000 micrometer (μm).  
   
   
       47 . The microfluidic device according to  claim 36 , wherein said polymer layer has a maximum thickness of about 1 centimeter.  
   
   
       48 . The microfluidic device according to  claim 36 , wherein the multilayer body further comprises at least one affinity agent immobilized on the micro-structure.  
   
   
       49 . A microfluidic device, comprising: 
 a plurality of polymer layers comprising a first polymer layer with hydrophilic surface properties and a second polymer layer with hydrophobic surface properties, said plurality of polymer layer having at least one micro-structure for performing analysis using electrochemical fluid properties.